Engine reman-Hypereutic pistons?

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PBKboater

Seaman
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Sep 25, 2007
Messages
65
Having my OMC 460 1988 remanufactured and would like to know if the Hypreutic pistons are the norm for marine eng application? Or are they just another marine piston like any other marine piston? Also what would you guys sugggest for the rings molly? I will be selling this boat for a bigger one but don't want to spend to much money and maintain a solid engine rebuild. I like to know the person that buys my boat will get alot of good seasons out of it. (do unto others sorta speak). Any other suggestion to look for and apply would be greatly appreciated.
PS: As I undersranfd the Hypereurtic piston are an all around piston not just for marine apps and are more robust piston and are good for marine apps due to the uneven temps in a marine block, true???

Thanks in advance
Paul
 
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HT32BSX115

Supreme Mariner
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Dec 8, 2005
Messages
10,083
Re: Engine reman-Hypereutic pistons?

Paul,

One of the other members did the very same thing at a local machine shop down the street. I was also going to have my 460 rebuilt by the same guy. (I did have him rebuild my 292 Y-Block) He told me that he uses an engine kit for a marine engine. He quoted me something like $1795 to "longblock" the engine. balancing, porting was a little extra.

You have a lot of other choices.

http://www.usenginesinc.com/marine.html

http://www.powerpro2000.com/diesel_lb_gm.htm (free shipping but look at the higher price)


I would just get the engine rebuilt at a local reputable machine shop (so if something goes wrong you can go back)


My original 460 ran almost 20 years with the "stock" pistons. you don't really need to worry about whether you have hype'd pistons or not unless you're going to build up a hype'd engine like a an 11:1 540 or something. You do that and you'll probably break the drive or spin the coupler.

Boat engines usually have low compression pistons because the most common gas available is 87 octane reg.....

IMHO, just replace the engine with good stock reman/rebuild and sell it.

I probably don't have to tell you this.......When you buy your next boat, ensure that it has either a Volvo Penta or Merc drive in it!!



Good luck

Rick
 
mkast

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: Engine reman-Hypereutic pistons?

According to a guy named Moore:
Heat Treated Hypereutectic Cast Pistons
It is important to understand that the hypereutectic pistons used in OEM engines and sold as replacements for stock use are not heat treated. High performance hypereutectic pistons are
T-6 heat-treated. Be sure that when purchasing aftermarket hypereutectic pistons you are getting the heat treated ones.

Advantages and Disadvantages:

The operating differences between forged and hypereutectic pistons are
significant. Because of the differences of the percentage of silicon between the forged and the hypereutectic pistons, the hypereutectic piston has a harder surface. Ring lands are stronger, the piston skirts will ride in the bores with less friction and cause less wear, and the piston will survive higher temperatures. The drawback to the hypereutectic piston is that the piston doesn't dissipate heat as fast as a forged piston. The top ring will run hotter, and wider end gaps are required to keep the end gaps from butting together. The piston manufacturer's specifications on ring end gaps should be followed very closely.

With that being said, the engine manufacturers have been using cast aluminum pistons for "how many years?"
 
P

PBKboater

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Messages
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Re: Engine reman-Hypereutic pistons?

Thanks Rick, Thats what I needed to hear! I will go ahead and have U.S motors in Kent Wa do the job with there marine package (standard pistons). I live a couple of hours away from them and don't mind the drive. They have a up to 3 year warranty (labor cost up to 45$ hr) As long as I follow the warranty guide lines, Oil sample ...etc. The new/used boat I have in mind is a bayliner 3270 MY, I really like the motor(s) and drive setup and the way they did the enterior. I know I'm stepping into a whole new world there! Unless you have another suggestion for a 30 to 35' boat? My wife and I like to fish and boat camp! Ok stepping into another forum area eh?

Thanks again for your input!

Paul
PS: Amen to the volvo / Mercruiser, Deffenantly will not buy another OMC!
Had a 305cu 280 volvo penta and that outdrive went thru 2 motors without a single problem. Those things are built like a truck axle!!!
 
P

PBKboater

Seaman
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Sep 25, 2007
Messages
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Re: Engine reman-Hypereutic pistons?

Mkast, I chimed in before seeing your reply. And wow! "excellent info" With that info also I will still go with standard pistons and not worry about it. I just needed some good input and advice which both you and Rick provided!
Thanks again guys and If interested I'll update with motor reman results.

Paul
 
C

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: Engine reman-Hypereutic pistons?

(I did have him rebuild my 292 Y-Block).

What old 50's/ early 60's Ford you put that In?
 
C

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: Engine reman-Hypereutic pistons?

Sweet; I have 46 F1, was modified to having a 383 dodge and t-flite, and a gm 12 bolt- that going to my son. 2 years ago, picked up a titled 49 ford p/u; think is a 50. No engine or rear fenders, running boards are worth more than the $1500 I paid. Has the original rear end and tranny(except top cover and shifter.
Started on hot rodding it, then 2 months later ended up with the boat- so truck been sitting.
 
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HT32BSX115

Supreme Mariner
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Messages
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Re: Engine reman-Hypereutic pistons?

Yeah. Boats will get yer money every time!!
 
D

dcg9381

Petty Officer 1st Class
Joined
Aug 26, 2007
Messages
308
Re: Engine reman-Hypereutic pistons?

Other than the modern EFI "Mag" motors - how many OEM motors come with forged slugs as original equipment? I would think that the norm is cast.
 
Big Boat Bay Buster

Big Boat Bay Buster

Petty Officer 2nd Class
Joined
Jul 1, 2007
Messages
118
Re: Engine reman-Hypereutic pistons?

I'm rebuilding a merc 260. I asked my machine shop guy the same question. He says there is notheing wrong with standard cast for my application. Also to stay away from the coated Hypereutric piston. He then showed me one where the coating wore off the skirt and the piston then had excessive clearence. Normal Hypereutic are fine. I will probably be getting a nice set of Hypereutic speed-pro slugs for mine. Now, What cam to use???????
Chris
 
Big Boat Bay Buster

Big Boat Bay Buster

Petty Officer 2nd Class
Joined
Jul 1, 2007
Messages
118
Re: Engine reman-Hypereutic pistons?

HT, that question was more of a joke than an actual question. But thanks for the link anyhow!
Chris
 
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